Electronic device

ABSTRACT

According to one embodiment, an electronic device includes: a casing comprising a display thereto, the casing being configured to house therein an electric component configured to generate heat; a wearing member configured to be wrapped around an arm of a human body to cause the casing to be worn on the arm; a plurality of electrodes configured to face, in a state that the casing is worn on an arm, a side of the arm; an impedance measurement module configured to measure impedance between two of the electrodes; and a controller configured to control the electric component so that when the impedance obtained in the impedance measurement module is lower than a threshold, an amount of the heat generated by the electric component becomes small compared with a case that the impedance is higher than the threshold.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority fromJapanese Patent Application No. 2012-238244, filed Oct. 29, 2012, theentire contents of which are incorporated herein by reference.

FIELD

Embodiments described herein relate generally to an electronic device.

BACKGROUND

Conventionally, there has been known an electronic device wearable on ahuman body.

In this kind of the electronic device, as one example, it is preferablethat the electronic device be capable of suppressing a temperature risewhile suppressing the degradation of performance thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

A general architecture that implements the various features of theinvention will now be described with reference to the drawings. Thedrawings and the associated descriptions are provided to illustrateembodiments of the invention and not to limit the scope of theinvention.

FIG. 1 is an exemplary perspective view of one example of an electronicdevice according to an embodiment;

FIG. 2 is an exemplary explanatory view illustrating a state that oneexample of the electronic device in the embodiment is worn on an arm ofa human body in a state that the arm is not covered with clothing;

FIG. 3 is an exemplary explanatory view illustrating a state that oneexample of the electronic device in the embodiment is worn on an arm ofa human body in a state that the arm is covered with clothing;

FIG. 4 is an exemplary plan view of one example of the electronic deviceas viewed from the contact surface side of the electronic device that isbrought into contact with an arm of a human body;

FIG. 5 is an exemplary block diagram of one example of the electronicdevice in the embodiment;

FIG. 6 is an exemplary flowchart illustrating one example of temperaturecontrol in the electronic device in the embodiment;

FIG. 7 is an exemplary plan view of one example of an electronic deviceaccording to a first modification as viewed from the contact surfaceside of the electronic device that is brought into contact with an armof a human body;

FIG. 8 is an exemplary plan view of an electrode unit in one example ofan electronic device according to a second modification; and

FIG. 9 is an exemplary plan view of an electrode unit in one example ofan electronic device according to a third modification.

DETAILED DESCRIPTION

In general, according to one embodiment, an electronic device comprises:a casing comprising a display thereto, the casing being configured tohouse therein an electric component configured to generate heat; awearing member configured to be wrapped around an arm of a human body tocause the casing to be worn on the arm; a plurality of electrodesconfigured to face, in a state that the casing is worn on an arm, a sideof the arm; an impedance measurement module configured to measureimpedance between two of the electrodes; and a controller configured tocontrol the electric component so that when the impedance obtained inthe impedance measurement module is lower than a threshold, an amount ofthe heat generated by the electric component becomes small compared witha case that the impedance is higher than the threshold.

A plurality of exemplary embodiments or modifications described belowcomprise similar parts. Therefore, hereinafter, the similar parts aregiven the same numerals and their repeated explanations are omitted.Furthermore, the parts comprised in the respective embodiments ormodifications can be substituted by corresponding parts of the otherembodiments or modifications.

Furthermore, in the following embodiments, a case that an electronicdevice is constituted as a tablet-type (slate-type) personal computerprovided with a wearing member is exemplified. However, an electronicdevice according to the present embodiment is not limited to theseexamples. The electronic device in the present embodiment is, forexample, a device wearable on (detachable from) a human body such as avideo display (a portable player), a smart phone, a mobile phone, apersonal digital assistant (PDA), a TV phone, an electronic bookterminal, or a television receiver, provided with parts (electric parts,electronic parts, or the like) in the inside of a casing, and can beconstituted as a device capable of performing display output, audiooutput, audio input, operation input, or the like.

Embodiment

In an embodiment, as one example illustrated in FIGS. 1 to 3, anelectronic device 1 comprises a casing 2 and a wearing member 3. Thecasing 2 houses at least a part of a display 4 (a display part, anelectric part) therein. Furthermore, the casing 2 houses a board 18 (acircuit board, a printed circuit board, electric parts) therein. Inaddition, the casing 2 is provided with a light emitting part 9 (a lightemitting diode (LED), a display part, or the like).

In the present embodiment, as one example illustrated in FIG. 1, thecasing 2 has the external appearance of a quadrangular shape (arectangular shape, as one example in the present embodiment) in a frontview (as viewed from the normal direction or orthogonal direction) andin a rear view with respect to a display screen 4 a of the display 4.The casing 2 is, as one example in the present embodiment, formed in arectangular parallelepiped shape being thin flat in the anteroposteriordirection (in the thickness direction of the casing 2). The casing 2 hasa face 2 a (a front, a front face, a surface portion), a face 2 b (arear face, a back face, a surface portion) opposite to the face 2 a, anda face 2 p (a side face, a surface portion) extending between the face 2a and the face 2 b. Each of the face 2 a and the face 2 b intersectswith the thickness direction of the casing 2. The face 2 a and the face2 b are substantially in parallel to each other. Furthermore, the face 2a and the face 2 b intersect with (are orthogonal to, as one example inthe present embodiment) the face 2 p. In addition, the casing 2 has fourend portions 2 c to 2 f (side portions, edge portions, peripheralportions) and four corner portions 2 g to 2 j (projecting portions,curved portions, end portions) in a front view. Each of the end portions2 c and 2 e is one example of a long side portion. Each of the endportions 2 d and 2 f is one example of a short side portion.

Furthermore, the casing 2 has a wall portion 2 k (a part, a plate, afront wall portion, a front side wall portion, a top wall portion, afirst wall portion), a wall portion 2 m (a part, a plate, a rear wallportion, a back wall portion, a bottom wall portion, a second wallportion), and wall portions 2 n (parts, plates, side wall portions, endwall portions, erected wall portions, extending portions, third wallportions). The wall portion 2 k has the face 2 a. The wall portion 2 mhas the face 2 b. Each wall portion 2 n has the face 2 p. Each of thewall portions 2 k, 2 m, and 2 n is formed in a quadrangular shape (arectangular shape, as one example in the present embodiment). Inaddition, each of the wall portions 2 k, 2 m, and 2 n is formed in aplate-like shape. The wall portion 2 k is provided with a quadrangularopening 2 r.

In addition, the casing 2 is constituted by combining a plurality ofparts (divided bodies, members). The casing 2 has, as one example, amember 21 (a front side member, a cover, a bezel, a plate, a firstmember) and a member 22 (a back side member, a base, a bottom, a plate,a second member). The member 21 comprises the wall portion 2 k. Themember 22 comprises the wall portion 2 m. The wall portion 2 n iscomprised in at least any one (the member 22, as one example in thepresent embodiment) of the member 21 and the member 22. The members 21and 22 can be, for example, composed of a metallic material or asynthetic resin material. The metallic material can be, for example,made by casting, pressing, or cutting. The synthetic resin material canbe, for example, made by injection molding. Here, the casing 2 can havemembers (not illustrated in the drawings) different from the members 21and 22.

Furthermore, in the present embodiment, as one example, the casing 2houses the display 4 (the display part, the display, the panel, thedisplay component) therein. To be more specific, a user can view thedisplay screen 4 a of the display 4 from the front side of the display 4through the opening 2 r. The display 4 has the external appearance of aquadrangular shape (a rectangular shape, as one example in the presentembodiment) in a front view. The display 4 is formed in a rectangularparallelepiped shape being thin flat in the anteroposterior directionthereof. The display 4 is, for example, a liquid crystal display (LCD),an organic electro-luminescent display (OELD), or the like. Here, thedisplay 4 may be a flexible display.

Furthermore, in the present embodiment, as one example, the display 4 isprovided with a transparent, relatively thin, and quadrangle-shapedinput operation panel 5 (a touch panel, a touch sensor, an operationscreen, an input operation part, an input reception part) on the frontside (the surface side, the wall portion 2 k side) thereof. The inputoperation panel 5 covers the display screen 4 a. An operator (a user,for example) performs input processing by operations such as touching,pushing, or rubbing with a finger, a stylus, or the like with respect tothe input operation panel 5, moving a finger, a stylus, or the like inthe vicinity of the input operation panel 5, or the like. Light emittedfrom the display screen 4 a of the display 4 passes through the inputoperation panel 5 toward the front side (the outside) of the casing 2from the opening 2 r of the wall portion 2 k. The input operation panel5 is one example of an input part. In addition, in the presentembodiment, as one example, the display 4 and the input operation panel5 are fixed to (supported on) the casing 2 by way of fixtures (fastenerssuch as screws, metal fittings, or parts, not illustrated in thedrawings), adhesive parts (adhesive agents, double-stick tapes, or thelike, not illustrated in the drawings). Here, the input operation panel5 may be constituted as an in-cell type touch panel comprised in thedisplay 4.

The wearing member 3 allows the wearing of the casing 2 (the electronicdevice 1) on a human body. In the present embodiment, as one example,the wearing member 3 is joined (fixed, connected) to the wall portion 2m of the casing 2. The wearing member 3 has a belt-shaped part 31 and afastener part 32. In the present embodiment, the belt-shaped part 31 is,as one example, wrapped around a forearm of a human-body arm 100 (seeFIGS. 2 and 3). The belt-shaped part 31 extends in a long belt shape (arectangular shape, a strip shape) along the short side direction of thecasing 2 (the direction along the end portion 2 d or 2 f, the lateraldirection in FIGS. 2 and 3). In the present embodiment, as one example,the width of the belt-shaped part 31 is substantially equal to the widthof the casing 2. The belt-shaped part 31 is provided with the fastenerparts 32 on both end portions 31 b in the longitudinal direction (in thedepth direction on the paper on which FIGS. 2 and 3 are drawn) of thecasing 2. In the present embodiment, as one example, the fastener parts32 are hook-and-loop fasteners capable of being attached and detached toeach other. The belt-shaped part 31 is wrapped around the forearm of thehuman-body arm 100 to fasten both fastener parts 32 thus wearing thewearing member 3 as well as the casing 2 (the electronic device 1) onthe arm 100. Here, as one example, the casing 2 is used in a state thatthe casing 2 is arranged on the elbow side of a wrist and a sidecoplanar with the back of a hand in a posture such that the longitudinalside of the casing 2 is placed along the arm 100.

When clothing 200 (a covering, see FIG. 3) does not exist (is notinterposed) between the arm 100 (the human body) and the casing 2 (theelectronic device 1) as illustrated in FIG. 2, the heat of the casing 2is easily transmitted to the arm 100 compared with a case that theclothing 200 exists (is interposed) between the arm 100 (the human body)and the casing 2 (the electronic device 1) as illustrated in FIG. 3.Accordingly, to consider a case where at least a part of the electronicdevice 1 is brought into direct contact with the arm 100 of a userwithout the clothing 200 interposed therebetween, when the electronicdevice 1 has higher temperature than the user with a certain level oftemperature difference, the user may feel uncomfortable. In this case,the electrical operation of the electronic device 1 may be suppressed toreduce heat generation. However, when the control of suppressing theheat generation from the electronic device 1 is constantly performed,for example, the operation of the electronic device 1 becomes slow thusinconveniencing the user. Therefore, in the present embodiment, as oneexample, the electronic device 1 is provided with a plurality ofelectrodes 6 exposed to the arm 100 side thereof (a surface 100 a of thearm 100), and the electrical operation of the electronic device 1 iscontrolled depending on the electrical characteristics of electricsignals between two (at least two, at least a pair of) electrodes 6.That is, in the present embodiment, as one example, when the measuredvalue of the electrical characteristics of the electric signals betweenthe two electrodes 6 is a value corresponding to a state that theclothing 200 is not interposed, the electrical operation of theelectronic device 1 is suppressed compared with the case that themeasured value is a value corresponding to a state that the clothing 200is interposed thus reducing the heat generation. That is, when themeasured value of the electrical characteristics of the electric signalsbetween the two electrodes 6 is a value corresponding to the state thatthe clothing 200 is interposed, the electrical operation of theelectronic device 1 is not easily suppressed compared with the case thatthe measured value is a value corresponding to the state that theclothing 200 is not interposed.

In the present embodiment, as one example illustrated in FIGS. 2 and 3,the electrodes 6 are projected from the casing 2 through the belt-shapedpart 31 and uncovered with surface 31 a at the arm 100 side of thebelt-shaped part 31. Therefore, the electrodes 6 face the arm 100 sidewhen the electronic device 1 is worn on the arm 100. As illustrated inFIG. 2, when the belt-shaped part 31 (the wearing member 3) is wrappedaround the arm 100 in a state that the clothing 200 does not exist, theelectrodes 6 are brought into contact with the surface 100 a (flesh,skin) of the arm 100. On the other hand, as illustrated in FIG. 3, whenthe belt-shaped part 31 is wrapped around the arm 100 in a state thatthe clothing 200 exists, the electrodes 6 are brought into contact withthe clothing 200. As illustrated in FIG. 3, when at least one of the twoelectrodes 6 (both electrodes 6, in FIG. 3) is brought into contact withthe clothing 200 (the covering), an electric current does not easilyflow between these two electrodes 6. On the other hand, as illustratedin FIG. 2, when both of the two electrodes 6 are brought into contactwith the arm 100, an electric current easily flows between these twoelectrodes 6 compared with the case that the clothing 200 is interposed.

In the present embodiment, as one example illustrated in FIG. 4, thebelt-shaped part 31 is provided with two electrodes 6 aligned along thewidth direction of the belt-shaped part 31 in the area of thebelt-shaped part 31 at the back side of the casing 2. The two electrodes6 are aligned along the width direction of the belt-shaped part 31 thusbeing, as one example, aligned in the longitudinal direction of the arm100. Therefore, as one example, both of the two electrodes 6 are easilybrought into contact with the surface 100 a of the arm 100 or theclothing 200 compared with the case that the electrodes 6 are notaligned along the longitudinal direction of the arm 100.

In the present embodiment, as one example illustrated in FIGS. 2 and 3,the electronic device 1 is provided with sensors 7 (temperaturedetectors) for detecting the temperatures of the electrodes 6. Theelectrodes 6 are brought into contact with the arm 100 (the human body)or the clothing 200 covering the arm 100 in a state that the electronicdevice 1 is worn on the arm 100 and hence, the temperature detected bythe sensors 7 can be considered as the temperature of the arm 100 or theclothing 200 under such a predetermined condition that the electrodes 6are not in the high temperature state. Furthermore, the electronicdevice 1 is provided with a sensor 8 (a second temperature detector) fordetecting the temperature inside the casing 2. The sensor 8 can beplaced in the vicinity of an electric component that generates heat (thedisplay 4, a CPU, a package mounted on the board 18, or the like). Thesensors 7 and 8 are, for example, thermistors, thermocouples, ortemperature sensor ICs.

In the present embodiment, as one example illustrated in FIG. 5, theelectronic device 1 is provided with a main controller 10, an inputmodule 11, an output module 12, a storage 13, an impedance measurementmodule 14, a temperature controller 15 (a controller), a clockcontroller 16, a display controller 17, and the like. The maincontroller 10 is, for example, a central processing unit (CPU). Theinput module 11 is, for example, the input operation panel 5 or othercomponent such as an operation button, a microphone, a keyboard, or aswitch (not illustrated in the drawings). The output module 12 is, forexample, the display 4, the light emitting part 9, or other componentsuch as a speaker or a buzzer (not illustrated in the drawings). Thestorage 13 is, for example, a volatile, nonvolatile, non-rewritable, orrewritable memory or a storage device such as a random access memory(RAM), a read only memory (ROM), a hard disk drive (HDD), or a solidstate drive (SSD). In the storage 13, a nonvolatile storage area alsostores therein data (threshold data, tables, or the like) used forcontrol (arithmetic processing) in the temperature controller 15. Theimpedance measurement module 14 (an electrical characteristicmeasurement module) feeds, for example, an extremely weak current (analternating current) from two electrodes 6 to the arm 100 (the humanbody) to measure an impedance (electrical characteristics) between theelectrodes 6. The impedance measurement module 14 can be constituted asan impedance measurement IC. The temperature controller 15 performs, forexample, the control of suppressing the heat generation of (lowering thetemperature of) various kinds of electrical components based on theresults of the measured impedance (the electrical characteristics) bythe impedance measurement module 14. The temperature controller 15 canbe, for example, constituted as a temperature control IC and constitutedas a part of the function of an embedded controller (EC) or a keyboardcontroller (KBC). Furthermore, the temperature controller 15 acquires atemperature (data) detected by the sensors 7 or 8 from a signal receivedfrom the sensors 7 or 8. The clock controller 16 lowers, for example,the clock frequency of the CPU in response to the instruction of thetemperature controller 15 to perform the control of suppressing the heatgeneration (lowering the temperature) of the CPU. The display controller17 controls the display 4 so that the predetermined images or videos aredisplayed on the display 4. In addition, the display controller 17lowers, for example, brightness in the display 4 or reduces a time untilthe display screen 4 a left unoperated becomes dark to perform thecontrol of suppressing the heat generation (lowering the temperature) ofthe display 4. Here, the main controller 10 refers to a table of thevalue of impedance (electrical characteristics) and the characteristicvalue of the human body (a body fat percentage or the like) that areassociated with each other, the table being stored in the storage 13,thus acquiring the characteristic value of the human body thatcorresponds to the result of the measured impedance. In this case, themain controller 10 can control the display controller 17 so that thecharacteristic value of the human body is displayed on the display 4.

The temperature controller 15 can change the light emitting state of thelight emitting part 9 depending on the result of the measured impedance(electrical characteristics). For example, when the impedance is smallerthan or equal to the threshold, the temperature controller 15 can turnon red light of the light emitting part 9. When the impedance is largerthan the threshold, the temperature controller 15 can turn on greenlight of the light emitting part 9. In addition, the temperaturecontroller 15 controls the display controller 17 thus controlling thedisplay 4 so as to perform a display corresponding to the result of themeasured impedance (the electrical characteristics). For example, thetemperature controller 15 can control the display 4 so that the measuredvalue of the impedance is displayed, a character such as “Skin” or a redmark is displayed when the impedance is low, or a character such as“Clothing” or a green mark is displayed when the impedance is high.

In the present embodiment, as one example, in the electronic device 1,the temperature control of electric components in the casing 2 isperformed in procedures illustrated in FIG. 6. First of all, theimpedance measurement module 14 (the electrical characteristicmeasurement module) acquires impedance (electrical characteristics)between two electrodes 6 (S1). Next, the temperature controller 15acquires the results of detected temperatures by the sensors 7 and 8(S2). Next, the temperature controller 15 compares the impedanceacquired with a threshold (S3). When the impedance is smaller than orequal to the threshold (Yes at S4), the temperature controller 15compares a temperature Tc in the inside of the casing 2 that is measuredby the sensor 8 with an allowable temperature Tx1 (an upper limittemperature) (S5). The allowable temperature Tx1 at S5 has, for example,a value obtained by adding the predetermined allowable temperature rangeΔT1 (3° C., for example) to a temperature Te of the electrodes 6 that ismeasured by the sensors 7. That is, in the present embodiment, as oneexample, the higher the temperatures of the electrodes 6 are, the higherthe allowable temperature Tx1 becomes. In comparison with thetemperatures at S5, when the temperature Tc is equal to or higher thanthe allowable temperature Tx1 (Yes at S6), the temperature controller 15performs the control of suppressing the heat generation (lowering thetemperature) of the electric components (a temperature control A, S7).To be more specific, at S7, as described above, the temperaturecontroller 15 transmits, for example, an instruction to the clockcontroller 16 or the display controller 17. In response to thisinstruction, the clock controller 16 reduces the clock speed of the CPU,and the display controller 17 lowers the brightness in the display 4 orreduces a time until the display screen 4 a left unoperated becomesdark. Furthermore, when the determination at S4 is No; that is, when theimpedance is equal to or larger than the threshold, the temperaturecontroller 15 performs the temperature control of moderately suppressingthe heat generation of the electric components compared with thetemperature control A. To be more specific, at S8, the temperaturecontroller 15 compares the temperature Tc in the inside of the casing 2that is measured by the sensor 8 with an allowable temperature Tx2 (anupper limit temperature) (S8). The allowable temperature Tx2 at S8 has,for example, a value obtained by adding the predetermined allowabletemperature range ΔT2 (larger than ΔT1, 6° C., for example) to thetemperature Te of the electrodes 6 that is measured by the sensors 7.That is, in the present embodiment, as one example, the higher thetemperature Te of the electrodes 6 is, the higher the allowabletemperature Tx2 becomes. In comparison with the temperatures at S8, whenthe temperature Tc is equal to or higher than the allowable temperatureTx2 (Yes at S9), the temperature controller 15 performs the control ofsuppressing the heat generation (lowering the temperature) of theelectric components (a temperature control B, S10). When the powersupply of the electronic device 1 is not OFF or not set to OFF (No atS11), the processing returns to S1. On the other hand, when the powersupply of the electronic device 1 is OFF or set to OFF (Yes at S11), thetemperature controller 15 stops a series of temperature controls. Here,in comparison with the temperatures at S5, when the temperature Tc isequal to or lower than the allowable temperature Tx1 (No at S6) and, incomparison with the temperatures at S8, when the temperature Tc is equalto or higher than the allowable temperature Tx2 (No at S9), theprocessing proceeds to S11. In the present embodiment, as one example,while the power supply of the electronic device 1 is ON, the abovementioned processing from S1 to S11 is repeated.

As explained heretofore, in the present embodiment, as one example, thetemperature controller 15 (the controller) controls, in S6 and S7 in thecase where the impedance is lower than the threshold (the temperaturecontrol A), an electric component so that the amount of the heatgenerated by the electric component becomes small (the temperature ofthe electric component becomes low) compared with S9 and S10 in the casewhere the impedance is higher than the threshold (the temperaturecontrol B). Therefore, in the present embodiment, as one example, whenthe electronic device 1 is brought into direct contact with the arm 100(the human body), the temperature rise of the electronic device 1 issuppressed compared with the case that the electronic device 1 isbrought into contact with the arm 100 with the clothing 200 (thecovering) interposed therebetween. Accordingly, as one example, a useris easily prevented from feeling uncomfortable. As one example, when thetemperature rise of the electronic device 1 is suppressed to the extentthat a user may not easily feel uncomfortable, the electrical operationof the electronic device 1 is not suppressed thus using the electronicdevice 1 in a higher-performance state.

In the present embodiment, as one example, the temperature controller 15sets the allowable temperature of the electric component higher alongwith an increase in the temperature detected by the sensors 7 (thetemperature detectors). Therefore, according to the present embodiment,as one example, when difference between the temperature of theelectronic device 1 and the temperature of the human body is not solarge and a user may not easily feel uncomfortable, the electricaloperation of the electronic device 1 is not suppressed thus using theelectronic device 1 in a higher-performance state.

In the present embodiment, as one example, the electrodes 6 have beenarranged along the width direction of the belt-shaped part 31 (thedirection in which the arm 100 extends when wearing the electronicdevice 1). Therefore, according to the present embodiment, as oneexample, the electrodes 6 are surely brought into contact with the arm100 or the clothing 200 compared with the case that the electrodes 6 arearranged along the circumferential direction of the arm 100.

First Modification

In the present modification illustrated in FIG. 7 also, an electronicdevice 1A has a constitution similar to that of the electronic device 1according to the above-mentioned embodiment. Therefore, the electronicdevice 1A can provide similar results to the case of the electronicdevice 1 in the above-mentioned embodiment because of its constitutionsimilar to that of the electronic device 1. In the present modification,as one example, the electronic device 1A is provided with three or more(four, as one example in the present modification) electrodes 6 (6A to6D). To be more specific, two electrodes 6A and 6B are aligned, in anarea on the back side of the casing 2 of the belt-shaped part 31, alongone end portion in the width direction of the belt-shaped part 31 in amutually spaced-apart manner. These two electrodes 6A and 6B are alignedalong the longitudinal direction of the belt-shaped part 31 thusaligning, as one example, in the circumferential direction of the arm100. Furthermore, two electrodes 6C and 6D are aligned, in an area onthe back side of the casing 2 of the belt-shaped part 31, along theother end portion in the width direction of the belt-shaped part 31 in amutually spaced-apart manner. These two electrodes 6C and 6D are alsoaligned along the longitudinal direction of the belt-shaped part 31 thusaligning, as one example, in the circumferential direction of the arm100.

Furthermore, the two electrodes 6A and 6C are aligned along the widthdirection of the belt-shaped part 31 in a mutually spaced-apart manner.Furthermore, the two electrodes 6B and 6D are also aligned along thewidth direction of the belt-shaped part 31 in a mutually spaced-apartmanner. In addition, the electrodes 6A and 6C are not located atpositions close to the end portion 2 c of the casing 2 but located atpositions close to a center line M extending along the width directionbetween end portions 2 c and 2 e, and the electrodes 6B and 6D are alsonot located at positions close to the end portion 2 e of the casing 2but located at positions close to the center line M. Therefore,according to the present modification, as one example, the electrodes 6Ato 6D are easily prevented from being separated (spaced) from the arm100 (the human body) or the clothing 200 (the covering) compared withthe case that the electrodes 6A to 6D are located at a position close tothe end portion 2 c or 2 e.

When the electronic device 1 is provided with three or more electrodes6, there exist at least three combinations of two electrodes 6. In thepresent modification, the impedance measurement module 14 can switch thecombinations of two electrodes 6 to be energized (used for measurements)to measure the impedance (the electrical characteristics) with respectto each of different combinations of the electrodes 6. The temperaturecontroller 15 controls, when impedance with respect to at least onecombination (between two electrodes 6) out of a plurality ofcombinations of two electrodes 6 is lower than a threshold, an electriccomponent so that the amount of the heat generated by the electriccomponent becomes smaller (the temperature of the electric componentbecomes lower). That is, according to the present modification, as oneexample, when the electronic device 1A is partially brought into contactwith the arm 100 (the human body) without the clothing 200 (thecovering) interposed therebetween, the temperature rise of theelectronic device 1A is easily suppressed more reliably.

In the present modification, in view of a state that the electronicdevice 1A is worn on the arm 100 (the forearm), one of a pair ofelectrodes 6A, 6B and a pair of electrodes 6C, 6D are located at an endportion on the wrist side of the belt-shaped part 31. Therefore, whenthe cuff of the clothing 200 is located at a middle portion in the widthdirection of the belt-shaped part 31 and the electronic device 1A ispartially brought into contact with the arm 100 (the human body) on theoutside of the cuff (the wrist side) without the clothing 200 (thecovering) interposed therebetween, one of the pair of electrodes 6A, 6Band the pair of electrodes 6C, 6D (the combination of electrodes locatedon the wrist side of the cuff) can be brought into contact with thesurface 100 a of the arm 100 on the outside of the cuff. Therefore, inthis case, the impedance measured between the pair of electrodes locatedon the wrist side of the cuff is lower than the threshold and hence, thetemperature controller 15 controls the electric component so that theamount of the heat generated by the electric component becomes smaller(the temperature of the electric component becomes lower). That is,according to the present modification, as one example, when theelectronic device 1A is brought into contact with the arm 100 on theoutside of the cuff of the clothing 200, the temperature rise of theelectronic device 1A is suppressed more reliably.

Second and Third Modifications

Each of an electronic device 1B according to the second modificationillustrated in FIG. 8 and an electronic device 1C according to the thirdmodification illustrated in FIG. 9 has a constitution similar to that ofthe electronic device 1 or 1A according to the above-mentionedembodiment or the first modification except that the electronic devices1B and 10 are provided with electrode units 60B and 60C respectively.Therefore, the electronic devices 1B and 1C in the second and thirdmodifications can provide similar results to the case of the electronicdevice 1 or 1A in the above-mentioned embodiment or the firstmodification because of their constitutions similar to that of theelectronic device 1 or 1A. Here, in the second modification illustratedin FIG. 8, the electronic device 1B is provided with the electrode unit60B in which a plurality of electrodes 6 (6E and 6F) are integrated withan insulating member 60 a (an insulator) interposed therebetween. Due tosuch a constitution, as one example, both of the two electrodes 6E and6F are easily brought into contact with the arm 100 or the clothing 200.Therefore, in the present modification, as one example, the measurementof the impedance (the electrical characteristics) using the twoelectrodes 6E and 6F can be performed with high accuracy. Furthermore,as one example, the two electrodes 6E and 6F are easily arranged closeto each other in a compact manner and hence, as one example, theflexibility of the layout of parts in the inside of the casing 2 of theelectronic device 1B can be easily increased. Here, the electrode unit60B in the second modification can be used as the electrodes 6A and 6Bor the electrodes 6C and 6D in the first modification. Furthermore, theelectrode unit 60C constituted by integrating the electrodes 6 (6G and6H) provided to the casing 2 of the electronic device 10 according tothe third modification illustrated in FIG. 9 can also provide similarresults (advantageous effects) to the case of the second modification.In the third modification, the electrode 6G is constituted in a columnarshape, the insulating member 60 a is constituted in a cylindrical shapeso as to surround the electrode 6G, and the electrode 6H is constitutedin a cylindrical shape so as to surround the insulating member 60 a.

For example, characteristics other than the impedance may be used as theelectrical characteristics. Furthermore, the number of electrodes may befour or more.

Moreover, the various modules of the systems described herein can beimplemented as software applications, hardware and/or software modules,or components on one or more computers, such as servers. While thevarious modules are illustrated separately, they may share some or allof the same underlying logic or code.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the inventions. Indeed, the novel embodiments described hereinmay be embodied in a variety of other forms; furthermore, variousomissions, substitutions and changes in the form of the embodimentsdescribed herein may be made without departing from the spirit of theinventions. The accompanying claims and their equivalents are intendedto cover such forms or modifications as would fall within the scope andspirit of the inventions.

What is claimed is:
 1. An electronic device comprising: a casingcomprising a display thereto, the casing being configured to housetherein an electric component configured to generate heat; a wearingmember configured to be wrapped around an arm of a human body to causethe casing to be worn on the arm; a plurality of electrodes configuredto face, in a state that the casing is worn on an arm, a side of thearm; an impedance measurement module configured to measure impedancebetween two of the electrodes; and a controller configured to controlthe electric component so that when the impedance obtained in theimpedance measurement module is lower than a threshold, an amount of theheat generated by the electric component becomes small compared with acase that the impedance is higher than the threshold.
 2. The electronicdevice of claim 1, further comprising: a temperature detector configuredto detect a temperature of the electrode, wherein the controller isconfigured to increase an allowable temperature of the electriccomponent or in an inside of the casing along with an increase in thetemperature detected by the temperature detector.
 3. The electronicdevice of claim 1, wherein the electrodes comprises three or moreelectrodes, and the controller controls, when the impedance between atleast any one combination out of a plurality of combinations of two ofthe electrodes is lower than the threshold, the electric component sothat the amount of the heat generated by the electric component becomessmall.
 4. The electronic device of claim 1, wherein the wearing membercomprises a belt-shaped part wrapped around an arm, and the electrodesare arranged along a width direction of the belt-shaped part.
 5. Theelectronic device of claim 1, wherein the wearing member comprises abelt-shaped part wrapped around an arm, and the electrodes are arrangedalong a longitudinal direction of the belt-shaped part.
 6. Theelectronic device of claim 4, wherein the wearing member comprises abelt-shaped part wrapped around an arm, and a plurality of rows of theelectrodes arranged along a longitudinal direction of the belt-shapedpart are arranged in the width direction of the belt-shaped part in aspaced-apart manner.
 7. The electronic device of claim 1, furthercomprising: an electrode unit configured to integrate the electrodeswith an insulator interposed therebetween.
 8. The electronic device ofclaim 1, further comprising: a display part configured to perform adisplay corresponding to at least one of a case that the impedanceobtained in the impedance measurement module is lower than a thresholdand a case that the impedance obtained in the impedance measurementmodule is higher than the threshold.
 9. An electronic device comprising:a casing comprising a display thereto; a wearing member configured to bewrapped around an arm of a human body to cause the casing to be worn onthe arm; a plurality of electrodes configured to face, in a state thatthe casing is worn on an arm, a side of the arm; and a controllerconfigured to control the display so that when the wearing member iswrapped around the arm without clothing interposed therebetween, a heatgeneration of the display is suppressed based on electricalcharacteristics of electric signals between the electrodes compared witha case that the wearing member is wrapped around the arm with clothinginterposed therebetween.
 10. An electronic device comprising: a casingcomprising an electric component thereto; a wearing member configured tocause the casing to be worn on an arm of a human body; a plurality ofelectrodes configured to face, in a state that the casing is worn on thehuman body, a side of the arm; and a controller configured to controlthe electric component so that when the wearing member is worn on thehuman body without a covering interposed therebetween, a heat generationof the electric component is suppressed based on electricalcharacteristics of electric signals between the electrodes compared witha case that the wearing member is worn on the human body with a coveringinterposed therebetween.